Clinimetric Properties of the Brief Fatigue Inventory Applied to Oncological Patients Hospitalized for Chemotherapy

Abstract

Background. The clinimetric properties of the Brief Fatigue Inventory (BFI) were not previously assessed in oncological patients hospitalized for chemotherapy. Objective. To assess the reliability and validity of the construct, ceiling and floor effects, and responsiveness of the BFI administered to oncological patients hospitalized for chemotherapy. Methods. This test-retest study included 100 oncological patients hospitalized for chemotherapy. The clinimetric properties tested were as follows: internal consistency (Cronbach's alpha), reliability (intraclass correlation coefficient [ICC2,1] and 95% CI), agreement (standard error of measurement and minimum difference changed [MDC90%]), validity of the construct (Pearson's correlation [r] with the Piper Fatigue Scale), responsiveness (effect size [ES] and correlation), and ceiling and floor effects (minimum and maximum score frequencies). The BFI was applied on the first day of chemotherapy and 48 hours and 15 days after the start of chemotherapy. Results. The BFI presented adequate values of internal consistency (a Cronbach = 0.94), substantial reliability [ICC2,1 (95% CI) = 0.87 (0.81 to 0.91)] and very good agreement (standard error of measurement = 1% and MDC90% =- 0.37). The BFI had a positive and strong correlation with the Piper Fatigue Scale (r = 0.84; P < 0.001). Internal responsiveness was considered moderate (ES = 0.5), and external responsiveness was absent. A floor effect was present (35%). Conclusion. BFI applied to oncological patients hospitalized for chemotherapy replicates its original version with adequate reliability, validity, and internal responsiveness. However, in this population, the BFI showed a floor effect.